That is a very cool old American pipe made by William Demuth Company,
https://pipedia.org/wiki/William_Demuth_Company
If you look at this image from what appears to be 1947, the Royal Demuth (it can be seen on the page linked to above) was available with a smooth Mahogany, Walnut "...or exciting unique Antique etched finish". If I had to guess, I would say the silver work was an added customized detail, perhaps it was a gift. Is there a triangle on the stem?